Atmospheric corrosion buildings

Atmospheric corrosion is probably that which is most evident to the layman. The pleasant green patina formed oh the roofs of many buildings is due to the even corrosion of the copper sheeting underlying the adherent corrosion products, which consist of basic copper carbonate and sulphates. Atmospheric corrosion occurs electrochemically and is due to the joint... 

Atmospheric corrosion involves various forms of corrosion effects at ambient temperature in which the Earth s atmosphere is the corrosive environment. Atmospheric corrosion has been recognized for several thousand years and the atmosphere is the most abundant environment to which solid materials are exposed. Hence, its implications in our society are enormous and range from bridges, elevated highways, railway and subway systems, aircraft, automobiles, and buildings, to industrial processes, electronic components and systems, to artistic or historic objects, such as statues and monuments. In the United States, for example, the total costs for all forms of corrosion have been estimated to be around 1000 US per capita per year. A substantial part of that amount is due to consequences of atmospheric corrosion. 

I.S. Cole, D.A. Paterson, Holistic model for atmospheric corrosion. Part 5—factors controlling deposition of salt aerosol on candles, plates and buildings, Corros. Eng. Sci. Tech. 39 (2004) 125—130. 

One of the few impressed current zinc systems in the United Kingdom at the time of going to press is shown in Figure 7.10. There has been some concern about the rise in resistance seen on some systems. This may be due to a build up of corrosion products between the zinc and the concrete, or to treatment of the zinc after application to protect it from atmospheric corrosion. Zinc, of course, is not inert and is consumed by corrosion from the atmosphere and water impingement. The anodic reaction also consumes the zinc and gives rise to the formation of oxides and sulphates at the anode/concrete interface which may increase the electrical resistance between anode and cathode. 

Absorption route Can enter the body by inhalation or ingestion. Harmful atmospheric concentrations build up fairly rapidly due to formation ofhydrochloric ac/tf fumes on exposure to air. immediate effects Corrosive to the eyes, skin and respiratory tract. Inhalation of vapor/fumes can cause severe breathing difficulties (lung edema). In serious cases risk of death. Effects of prolonged/repeated exposure Can cause heart, liver and kidney damage. ... 

Absorption route Can enter the body by ingestion. Evaporation negligS)le at 20 C. but harmfull atmospheric concentostlons build up rty slowly on evaporation at 20° C, but harmful concentrations can build up rapidly on contact with moisture or in the form of airborne particles. Imniodiale effects Corrosive to the eyes and skin. ... 

Absorptton route Can enter the body by inhalation or ingestion. Harmful atmospheric concentrations build up very slowly. If at al. on evaporation at approx. 2CTC, but harmfijl concentrations of airborne particles can build up much more rapidly. knraedlate effects Corrosive to the res. In substential cor>centrations can cause muscle weakness and tingling in arms and le Inh tion can cause severe brtoAMng dfficulfies (astoma). ... 

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